3ME-128
UNITED STATES ATOMIC ENERGY COMMISSION
GRAND JUNCTION OPERATIONS OFFICE
PRODUCTION EVALUATION DIVISION
VASTER
MINERALOGY AND PETROLOGY OF THE URANIUM DEPOSITS OF
CANE SPRINGS CANYON, SAN JUAN AND GRAND COUNTIES, UTAH
By
Alice S. Corey
TV* repo*I was prepared *t an account «f work
iponaorad hy the l ivtad States Government Neither
the United States nor the United States tnergy
Research and Development Ad ms mat rat ion. nor any of
then employees nor any of then contractors,
subcontractors, or than empkyces. makes any
tMrranty. er press or imp bed or aaawmes any k-gal
habdity or responadtdity for the accuracy, comptrtenesa
or umfulnesa of any information, apparatus product „t
pvoceK dtacioard. or represents tha' its use would not
infringe pnvatefy onmad rghti
May, 1959
(Grand Junction, Colorado)
OJSrftiBLl iUN Qf-
[H|s O'JL J.VE
is UNLIMITED
OFFICE MEMORANDUM
UNITED STATES GOVERNMENT
TO s R. D. Nininger, Assistant Director DATE: MAY 2 2 ^59
for Exploration, DRM, Washington
FROM : Elton A. xoungberg, Assistant Manager
for Operations, Grand Junction
SUBJECT: TRANSMITTAL OF REPORT RME-128
SYMBOL: P:DDB .
Transmitted herewith are copies 1, 2, 3, and U of a report by
Alice S. Corey, entitled "Mineralogy and Petrology of the
Uranium Deposits of Cane Springs Canyon, San Juan and Grand
Counties, Utah."
Distribution has been made as shown on the distribution sheet.
Enel:
1. Report (copies 1, 2, 3, and U)
CC: A. E. Jones w/encl.
D. D. Baker w/encl.
J. G. Barry w/encl.
M. L. Reyner w/encl.
J. F. Foran w/encl.
E. W. Grutt w/encl.
A. E. Granger w/encl.
H. B. Wood w/encl.
T. B. Nolan w/encl.
Prank Stead w/encl.
R. A. Beard w/encl.
N. B. O’Rear w/encl.
Prod. Sere. Br. w/encl.
Mineralogy Laboratory w/encl.
Alice S. Corey (Author) (for cement) w/encl.
RME-128
UNITED STATES ATOMIC ENERGY COMMISSION
GRAND JUNCTION OPERATIONS OFT ICE
PRODUCTION EVALUATION DIVISION
MINERALOGY AND PETROLOGY OF THE URANIUM DEPOSITS OF
CANE SPRINGS CANYON, SAN JUAN AND GRAND COUNTIES, UTAH
By
Alice S. Corey
May, 1959
(Grand Junction, Colorado)
-1-
RME-128
CONTENTS
Abstract. 8
Introduction ••••••. . ............ 8
Location g
Purpose g
Scope and methods g
General geology and structure...10
Mineralogy and petrology • •••••* . . . 14
Hercules prospect 14
Honeybee mine 14
Lithology 14
Metamorphism 16
Organic material 18
Post-fault primary minerals 19
Oxidized minerals 20
Paragenesis 21
Honeybee No. 2 mine 21
Lithology 21
Organic material 22
Post-fault mineralization and alteration 22
"B n Prospect 22
Canary shaft 24
Moonshine claim 24
Red Zero claim 25
Moss Back adit 25
Lithology 25
Organic material 25
Uranium and associated minerals 26
Oxidation 26
Paragenesis 28
Adair mine 28
Lithology 28
Organic material 28
Uranium and associated minerals 29
Oxidation 30
Paragenesis 30
Climax School Section mine 30
Lithology and organic material 31
Uranium and associated minerals 31
Oxidation 33
Paragenesis 33
Chemical and radiometric analyses of ore ...34
Physical characteristics of the organic material ••••••••••35
Sample locations and physical descriptions 35
Testing procedures 35
Calculations and results 37
Discussion 38
-3-
CONTENTS (Cont»d)
Color differences in the Cutler formation
Page
38
Summary...41
References. 64
ILLUSTRATIONS
Figure 1. Location of Cane Springs Canyon, San Juan
County, Utah . •...• • . . . 9
2. Relative thickness and intensity of gray-green
coloration in the Chinle formation. Cane Springs
Canyon, San Juan County, Utah . .....11
3. Columnar section. Cane Springs Canyon ..12
4* East side of Cane Springs Canyon showing structure
and mines.....13
5. Thin section, calcite-cemented sandstone.
Honeybee mine.42
6. Quartz-mica schist in fault zone. Honeybee mine .... 42
7* Polished section. Spaces between calcite crystals
and grains filled with chalcopyrite. Honeybee mine • • 43
8. Polished section. Chalcopyrite and uraninite as re¬
placement barite. Honeybee mine.43
9. Polished section. Mass of montroseite which has
replaced biotite along cleavage planes, veined by
chalcopyrite.44
10. Polished section. Uraninite and chalcopyrite in
pyrobitumen Honeybee mine. .44
11. Chalcopyrite veining pyrobitumen, and uraninite in
quarts. Polished section. Honeybee mine . .45
12. Uraninite veining chalcopyrite pseudomorphs of bomite.
Polished section. Honeybee mine.. .... 45
13. Uraninite veinlet extending from pyrobitumen into barite
schist. Polished section. Honeybee mine .. . 46
14. Chalcopyrite and uraninite in ankerite. Polished section.
Honeybee mine •••••• . 46
-4-
ILLUSTRATIONS (Cont»d)
Page
Figure 15. Uraninite disseminated in ankerite and pyrobitumen.
Polished section. Honeybee mine 47
16. Honeybee No. 2 mine along minor fault.47
17. Red sandstone bleached along fractures. Honeybee mine. 48
18. Fossil wood replaced by uraninite, calcite, and
pyrite. Polished section. Moss Back adit.48
19. Uraninite veined by organic matter. Polished section.
Moss Back adit .. 49
20. Fossil wood with uraninite. Polished section.
Moss Back adit. 49
21. Fossil wood with pyrite.. 30
22. Alternating pyrite and calcite. Polished section.
Moss Back adit .. 50
23. Pyrite in calcite. Polished section. Moss Back adit. 51
24. Pyrite after fossil wood. Polished section.
Moss Back adit .... 51
25. Alternating marcasite and calcite. Polished section.
Moss Back adit .•••••-• . 52
26. Calcarenite from Adair mine. Thin section. 52
27. Montroseite and calcite cementing sandstone, with
uraninite. Polished section. Adair mine . . 53
28. Fossil wood with uraninite, chalcopyrite, calcite,
and pyrite •.... . 53
29. Coalified wood with calcite and pyrite. Polished
section. Adair mine ...... . ... 54
30. Fossil wood replaced by uraninite, chalcopyrite,
pyrite, and calcite. Polished section. Adair mine • 54
31. Sandstone cemented by uraninite and calcite.
Polished section. Adair mine. 35
32. Sandstone cemented by montroseite replacing mica ... 55
33. Cell texture in fossil wood retained by uraninite
and calcite. Polished section. Adair mine ..... 56
-5-
ILLUSTRATIONS (Cont»d)
Figure 34. Fossil wood replaced by uraninite and calcite witn
galena. Polished section. Adair mine . . 56
35. Sandstone cemented by uraninite and calcite.57
36. Uraninite, pyrite, and calcite cementing sandstone.
Polished section. Climax School Section mine .... 57
37. Photomicrograph of fossil wood with uraninite and
calcite. Polished section .... . 58
38. Massive uraninite cut by calcite. Polished section.
Climax School Section mine ..58
39. Pyrite, uraninite, and calcite in fossil wood.
Polished section. Climax School Section mine .... 59
40. Massive pyrite veined by calcite and uraninite.
Polished section. Climax School Section mine .... 59
41. Uraninite along crystal planes of calcite. Polished
section. Climax School Section mine . 60
42. Pyrite crystal partly replaced by uraninite and
calcite. Polished section. Climax School Section
mine ••••••••••••••••..••••... 60
43. Pyrite crystals and masses which have veined and
partly replaced uraninite. Polished section.
Climax School Section mine.61
44. Remnants of cell texture. Polished section. Climax
School Section mine . ..... 61
45. Uraninite, pyrite, covellite, chalcocite, and
chalcopyrite in sandstone. Polished section.
Climax School Section mine ..62
46. Beta-zippeite - and uraninite-cemented sandstone.
Thin section. Climax School Section mine ...... 62
47. Veinlet of beta-zippeite in sandstone. Thin section.
Climax School Section mine.. 63
48. Boltwoodite needles in gypsum veinlet cutting beta-
zippeite-cemented sandstone ..... . ... 63
-6-
TA3LES
E&Ci
Table 1. Semi-quantitative spectrographic analyses of selected
samples from the fault zone in the Honeybee mine • • . • 17
2. Assays of selected samples.23
3« Results of physical tests ....36
4* Chemical and spectrographic analyses of "bleached”
and "unbleached" Cutler rock.. 39
-7-
RME-128
MINERALOGY AND PETROLOGY OF THE URANIUM DEPOSITS OF
CANE SPRINGS CANYON, SAN JUAN AND GRAND COUNTIES, UTAH
ABSTRACT
Uranium deposits in Cane Springs Canyon are on the northeast limb of
the Cane Creek anticline. Ore occurs in the Moss Back member of the Chinle
formation and the Moenkopi formation of Trlassic age, and the Cutler and
Rico formations of Permian age. The deposits on the east side of the
canyon are chiefly confined to faults and Joints while those on the west
side are replacements of channel-fillings near fractures. The major ore
mineral is uraninite which is invariably associated with organic matter.
Secondary uranium minerals, including andersonite, camotite, beta-sippeite,
and boltwoodite, are present at and near the surface. Vanadium and copper
minerals are widespread, but not abundant.
As a result of local "dislocation metamorphism", biotite-quartz
schist has formed in the fault zone in the Cutler formation.
The organic matter present in the area is pyrobitumen whose physical
properties were determined by testing.
Color variations in ore zones and in country rock are due principally
to presence or absence of hematite. Hematite is less-coMon in and near
faults and fractures, whether or not they are ore-bearing.
INTRODUCTION
Location
The uranium deposits of Cane Springs Canyon are in San Juan and Grand
Counties, Utah, approximately 8 air miles southwest of Moab. Access to
the area from Moab is gained via a gravelled road southward along the
south side of the Colorado River and thence upstream along Cane Creek (fig. 1).
Private roads lead to the various mines from the access road.
Purpose
The study of the mineralogy and petrology of the uranium deposits of
the area was originally undertaken to investigate the possible relations
between the various color differences in the host rock and the uranium
mineralisation, and to study the differences, if any, between the "vein-
type" deposits on the east side of the canyon and the "bedded" deposits
on the west side. The study also included detailed mineralogic and
petrographic investigations of the uranium ore and host rock and tests on
uranium-bearing organic matter.
Scope and methods
This study of the Cane Springs Canyon deposits was started in March,
1957. The mines studied are: Hercules, Honeybee, Honeybee Na 2, "B-prospect",
—8—
Canary* Moonshine, Red Zero, (fig. 2) and "Moss Back adit" on the east side
of Cane Creek, and the Climax School Section mines o~ the west side. A
total of 60 thin sections, 45 polished thin sections, and 90 polished sections
of ore and country rock were examined in the laboratory. X-ray analyses of
various minerals were made in the Denver laboratory of the U. S. Geological
Survey by th* writer. Spectrographic analyses were made by the U. S.
Geological Survey staff in the Denver laboratory and by E. B. Gross in the
U. S. Atomic Energy Coonission Mineralogy Laboratory at Grand Junction, Colorado.
Quantitative chemical analyses for ferrous and ferric iron content were made
by Brown Laboratory, Grand Junction. The Grand Junction laboratory of
Lucius Pitkin, Inc., made assays for U 30 g, eU308, V 2 O 5 , and Cu.
GEMERAL GEOLOGY AND STRUCTURE
Rocks exposed in Cane S}rings Canyon (fig. 2) include the Rico and
Cutler formations of the Perm.an age, the Moenkopi and Chinle formations
and Wingate sandstone of Triassic age, and the Kayenta formation of
Jurassic age. A stratigraphic section from McRae (1958) is shown in fig. 3.
Uranium deposits are found in all formations from the Rico formation to the
Moss Back member of the Chinle.
In the vicinity of the uranium deposits. Cane Springs Canyon intersects
the Cane Creek anticline. This structure is a slightly asymmetrical fold
about 15 miles long and 4 to 5 miles wide, trending N. 50° W. and plunging
20 NW. Baker (1933) believes that the anticline was first formed at the
end of the Permian, with a second period of deformation after Moenkopi time
and a third at the end of the Cretaceous, during which time "most of the
structural features of the area are believed to have acquired their present
form" (Baker p. 78). The flow of the salt in the Paradox formation was not
the cause o' the folding, but "after an anticline had started to form,
regional pressure exerted on the plastic salt would tend to cause it to
flow and accumulate under the areas which offered relief from the pressure —
namely, the upward-bowing anticlinesj consequently the anticlines would
have greater growth than pressure on nonplastic rocks would have caused"
(Baker p. 76).
Several high-tngle normal faults are present in the area. The Cane
Creek fault (fig. 2) strikes N. 4 O 0 W., dips steeply northeast, and has
been traced for approximately 2^ miles. In the SW £ of sec. 13, T. 27 S.,
R. 21 E. it has a displacement of 40 feet (McRae, 1958). In sec. 3, T. 27 S.,
R. 21 E., north of the Honeybee mine, two other steeply dipping normal faults
strike N» 32° W. and N. 70° W. (idem, 1958). Numerous other faults and
joints occur in the vicinity.
All of the deposits in the area are on the northeast flank of the Cane
Creek anticline (fig. 4). Most occur in or near the northeasterly dipping
fractures of northwest-trending fault zones. The deposits, including the
"bedded" deposits on the west side of the canyon, may be classified as vein
deposits according to the definitions of veins given by Lindgren (1933),
Qnmons (1940) and others. The ore bodies on the east side of the canyon
are chiefly confined to the faults and joints and are veins of the fissure
type. Those on the west have replaced wall rock in channels near fractures.
-10-
Uurotlit
Jr Ni*a,o >ond stone
Jk Koyentj tormotun
Trioiiie
kwW ngilt iondt'one
*c Chmie formation
Tim Moankoo' foima*ion
Permian
Pc Cutlar formation
Pr Rico formation
Width ond intensity of shading
represents thickness and
intensity or grey-green
altorotion in the Cltrnto
formotion
1/t _, i Mfc. f
Modified U5.8.S. phorogro og<c bate
Figure 2. Relotive thickness ana intensity of grey-green coloration m the Chinle
formation, Cane Springs Canyon, San Juan County, Utah
So a*.*©***. Bedd*--. •« 1 f ■«>
geo.*#!. g' .. »* 'J 3 j*', C '•
3¥#»tfOf O^d , *' s , *>CO *. vtt' 3 3‘
S COtO'M*' '*0 3»*d >3 if'C# *
«•*»« ». es * »c**» ♦&*» •* rflff
Vw<n»one. «ti »•#».
bj**. c*>e'Oct*f icu
Sm' p"j^ b'ach m>»
a**"" 4
^dVo *
anil k,ckf.c^«ia»«. amoiic.-ed. »
a.>a '«»?•*. »m»i# *d »o b'ow'’, wibC'C-i'oi#
5 o' , flstoa*,cc»' 9 ioir#roH.
-ta.pyipif 0 'h<**'C.
•»■*► >Mn D*d? of mO'-ne
iiir-*5»on«
■ 0O Honrontol and
"■ «*rt>cai kco >9
Mo. 1959 RME 128
No** Socfioo m*o*uffd
after
Columnar section, Cone Springs Conyon, Son juon County, Utah
MINERALOGY AND PETROLOGY
Uranium in the early ore shipments from each mine was prerent chiefly
in secondary minerals. These minerals include andersonite, Na 2 Ca(U 02 )( 003 ) 3 .
6H?0, beta-zippeite, (U 02 ) 2 (S 04 )( 0 H) 2 * 4 H 20 , camotite, K 2 (U 0 o) 2 (V 04 ) 2 *l- 3 H 20 ,
boltwoodite, K 2 (U 02 ) 2 ( s i° 3 ) 2 ( 0 H) 2 * 5 H 20 (Frondel and Ito, 1956), sharpite,
(U 02 )(C 03 )*H 20 , and masuyite, UO 3 . 2 H 2 O. Mining at greater distances fran the
surface has resulted in the discovery of uraninite in most of the mines. In
each instance the uraninite is in or near organic matter probably derived
from plant remains which have since been metamorphosed to pyrobitumen.
Vanadium minerals obseived are montroseite, VO(OH), vanadium clay, and
camotite. Copper minerals include chalcopyrite, bomite, chalcocite,
covellite, and malachite. Pyrite is ubiquitous, occurring in varying quantities
in the deposits. Marcasite is less common.
The detailed mineralogy and petrology of the ore, host rock, and
surro-nding country rock will be discussed in ascending stratigraphic order
for each mine.
Hercules Mine
Uranium in the Hercules property (fig. 4) is in a northwest-trending
fault zone in the Rico formation. Ore was removed from a shallow trench
which parallels the fault. The Rico formation here is mainly arkose that
contains a little mica, with calcite and hematite cement. The fault¬
filling consists of arkose, and of quartz-biotite schist formed by meta¬
morphism of the arkose during faulting. The metamorphisn is discussed below
in the section on the Honeybee mine.
Secondary uranium mineralization in the Hercules formed disseminations
and stringers of camotite in the fault zone and for a few inches into the
wall rock. No primary uranium mineral was found.
Honeybee mine
Most of the ore mined on the east side of Cane Creek has come from the
Honeybee mine (fig. A) in the Cutler formation. The ore is in and near a
northwest-trending, northeast-dipping fault zone.
Paul F. Kerr (oral conmrunication 1957) reports that an age determination on
Honeybee ore by J. L. Kulp resulted in a value of 50 to 60 million years.
Lithology
The rocks of the Cutler formation examined in thin section consist
mainly of poorly sorted arkosic sandstone cemented by calcite. The detrital
grains consist of quartz, feldspar, varying amounts of mica, and accessory
zircon, tourmaline, magnetite, chlorite, carbonaceous matter, and fragments
of chert and granite. Grains vary in size from very fine to very coarse
sand, but are mostly of medium size. The feldspar varies from fresh through
all stages of alteration to sericite or kaolinite. Biotite and muscovite
occur as large flakes or laths which are typically bent and twisted around
more-resistant detrital minerals, although most of them lie with the longer
dimensions parallel to the bedding planes.
- 14 -
The principal cement is calciie which varies from fine- to coarse¬
grained. In some zones the detrital grains have been corroded so that almost
none are in contact. Here the interstices are filled with calcite, which
is usually microcrystalline. It is not known whether the solutions that
corroded the grains and those that deposited the calcite were the same.
Calcite has replaced some of the detrital grains either partly or wholly
(fig. 5).
Locally hematite is an important cementing and coloring material.
The boundary between hematitic and non-hematitic rock is characteristically
quite sharp. Hematite also forms a thin coating on some grains that are
cemented mostly by calcite. Megascopically these rocks are generally of a
lighter tint of red than the ones cemented by hematite alone. Where the
grains have been corroded and replaced by calcite, the original boundaries
may be marked by a thin band of hematite (fig. 5). Occasional veinlets
of calcite cut across the calcite-cemented sandstone.
Within the mine minor amounts of clay-cemented sandstone, siltstone,
and mudstone or shale were observed interlayered with the calcite-cemented
arkose, but these rock types were not sampled at the surface because their
outcrops are either covered or inaccessible.
The rock in the fault zone consists f calcite- and clay-cemented
sandstone, minor siltstone and shale, and the metamorphic equivalents of
these sedimentary rocks. During the process of faulting much of the
argillaceous and feldspathic rock in the fault zone was altered. The amount
of alteration is variable and the rock grades from unaltered sandstone,
siltstone, and shale or mudstone to biotite-quartz schist (fig. 6).
Megascopically the non-uraniferous biotite-quartz schist varies from
silvery green to dark green in color, and the uranium-bearing schist is
dark gray to black. In thin section, the well-developed schist is seen to
contain biotite, quartz, and varying amounts of muscovite and feldspar. The
biotite is dark green to Almost black in hand specimen. Microscopically
it is pleochroic from dark green or brownish green to pale green, tan, or
almost colorless. Mica crystals are as much as 1 millimeter in the longest
dimension, but in the less well-developed portions of the schist they are
much smaller. The quartz grains are only slightly fractured despite the
evident faulting and metamorphism.
No quantitative determinations nor statistical studies were made of the
feldspar content of the schist compared to that of the unmetamorphosed
country rock because the sampling was not extensive enough for such studies.
In the thin sections examined, however, the feldspar content of the quartz-
biotite schist appears to be much less than that in the unmetamorphosed
Cutler arkose. In addition, the percentage of detrital mica is much lower
in the sections of faulted rock than in the country rock.
There are all gradations from biotite-quartz schist to unmetamorphosed
country rock within relatively short distances. A single thin section may
contain calcite- or clay-cemented sandstone at one end, and well-developed
biotite-quartz schist at the other, with either a gradation or a sharp
boundary between the two.
- 15 -
Portions of the faulted rock are rich in hematite and are colored
various shades of red. Hematite is present in the unaltered sandstone,
siltstone, and mudstone, and in all gradations of their metamorphic counter¬
parts. At most places streaks of hematite in the fault parallel the strike
and dip of the fault and also of the schistosity of the biotite-quartz
schist.
MBtfUBorphiaa
The biotite-quartz schist is a politic schist belonging to the biotite-
chlorite subfacies of the greenschijt facies described by Turner (1948),
Barth (1952), Ramber^ (1952), and others. It corresponds to the biotite
zone of Harker (1939'. Rocks of the greenschist facies are metamorphic rocks
of the lowest grade, recrystallized in the range of 100 to 250 degrees C.
(Barth, 1952, p. 334) and moderate pressure (1000 to 1500 atmospheres) (ibid.,
fig. 137, p. 349). The greenschist facies, with its subfacies, is one of
the normal products of regional metamorphism. These same products may also
be derived by "local dislocation metamorphism" (Turner, 1948, p. 9) where
the effects are "localized in proved dislocation zones".
No chlorite was observed in any of the sections from the Honeybee mine.
The presence of biotite and absence of chlorite may indicate that meta-
morphism proceeded beyond the chlorite stage and converted any chlorite
formed to biotite. On the other hand, chlorite may never have been present,
probably because of lack of the proper constituents, mainly magnesium.
Magnesium does not exceed 1 percent in the samples analyzed spectrographically
(Table I).
One feature which points to the latter hypothesis is the presence of all
gradations from well-developed biotite schist through biotite-bearing
phyllite to shale, and clay-cemented sandstone, within very short distances.
This indicates that the distribution of heat and pressure was irregular
during faulting and that the mineral assemblage never reached equilibrium.
Turner and Verhoogen (1951, p. 466) state that "owing to the extremely low
velocity of chemical reaction between crystalline minerals throughout the
lower range of metamorphic temperatures, chemical adjustment of a rock to
such temperatures seldom proceeds beyond an incipient stage unless under the
accelerating influence of synchronous deformation...and even where chemical
reconstitution has been complete and deformation strong, disequilibrium is
frequent in the mineral assemblage". According to Barth (1952), "the low
temperature and, generally, the surface-near conditions have hindered the
attainment of internal equilibrium". If the biotite-quartz schist were
produced from the original sedimentary rocks via a chlorite schist inter¬
mediate stage, it sems likely that some chlorite would remain, especially in
the intermediate zones between well-developed schist and unmetamorphosed
sandstone and siltstone.
None of the biotite-quartz schist at Cane Creek shows laminated structure
resulting from segregation of minerals into alternating layers paralleling
the schistosity, a feature which is common in many schists. The mica is
commonly somewhat twisted, which, according to Williams, Turner, and Gilbert
(1954, p. 217), may indicate that "internal movements persisted to the close
of metamorphism". No granulation nor undulatory extinction is observable in
-16-
•17-
Table 1
Semi-quantitative spectrograph!c analyses of selected samples from the fault zone in the Honeybee mine
Analyst:
E. B. Gross
(1)
(2)
(3)
(4)
(5)
(6)
(7)
(8)
(9)
(10)
A1
>10.
>10.
10.
>10.
>10.
5.
5.
5.
1.
.1
Ba
.005
.001
tr
.001
.001
tr
.01
.05
.01
.05
Ca
.1
.1
.1
.5
5.
.5
.5
.5
.5
.5
Cu
.005
.005
.005
.1
.05
.05
.1
.5
.1
.1
Efi_
10.
1.
1.
1.
5.
.5
.5
.5
1.
Mg
.i
.1
1.
.1
.05
1.
.5
.005
.005
.005
Mn
< .001
< .001
< .001
<.001
<.001
< .001
<.001
<.001
.005
.001
Mo
0
0
0
0
0
0
0
0
0
0
Na
5.
5.
5.
5.
5.
1.
5.
<.l
.5
<.l
Pb
0
0
0
.01
.005
0
0
.01
.ul
.1
Si
>10.
>10.
>10.
>10.
>10.
>10.
>10.
5.
5.
5.
Sr
0
0
0
0
0
0
0
0
0
0
Ti
.1
.5
.1
.05
.1
.1
.5
.005
.005
.005
U
0
0
0
0
.5
.5
1.
>10.
>10.
>10.
V
_ti_
_ti_
_ti_
_it_
_L_
_ti_
_It_
_ii_
_ti_
_.1_
Figures are reported to the nearest number in the series 10, 5, 1, .5, .1, etc., in percent,
0 = Looked for, but not detected.
(1) Rock types intermediate between sediments and biotite schist: some metamorphic mica and some clay.
(2) Rock types Intermediate between sediments and biotite schist.
(3) Rock types intermediate between sediments and biotite schist.
(4) Biotite schist and rock types intermediate between sediments and biotite schist.
(5) Biotite schist and rock types intermediate between sediments and biotite schist.
(6) Biotite schist (ore).
(7) Biotite schist and rock types Intermediate between sediments and biotite schist (ore).
(8) Shale and rock types intermediate between sediments and biotite schist (ore).
(9) Biotite schist (ore).
(10) Biotite schist (ore).
the quartz. The grains are angular, but so are most of the detrital grains
in the unmetamorphosed Cutler arkose. Because of its variability in the
country rock, grain size does not help in determining whether the quartz
has been granulated. Although feldspar is much less abundant in the well-
developed schist than the average in the country rock, it is not completely
absent. The small amount present is probably of detrital rather than meta-
morphic origin. No garnets nor amphiboles were observed, indicating that
the degree of metamorphism remained low.
The biotite-quartz schist, then, is a product of low grade metamorphism
produced on a small scale by local dislocation. The elements that were
recrystallized into biotite were derived from the original constituents of
the rock: potassium from orthoclase, microcline, mica, and hydromica;
aluminum from clay and feldspar; silicon from feldspar, mica, clay, and quartz;
iron from hematite; and oxygen from any of the minerals named.
Some calcite was crystallized later than the formation of the schist
since it occurs in veinlets cutting across the schistosity. However, much
of it probably crystallized during metamorphism. According to Barth (1952,
p. 335), "if the carbon dioxide pressure is insufficient, neither calcite
or dolomite will be able to grow. But field observations indicate that
circulating carbonate-bearing solutions are almost always present in this
type of rock (of the greenschist facies), that is, in lime-rich rocks almost
always calcite (or dolomite) are able to form. To be sure, no lime-rich
silicate close to the C-comer (of the ACF diagram) is stable in this facies.
Thus no choice is left to a lime-rich rock; either calcite has to develop
or the rock has to change its composition”.
Organic material
During the period of faulting the organic material in and near the fault
zone was altered and redistributed. The organic matter present today in
the fault in the Honeybee mine has been metamorphosed beyond the stage
where its origin can be definitely determined. Although there is some carbon¬
aceous material present in the unaltered Cutler arkose, there is a much higher
proportion in the fault zone. It seems likely that this was derived from
sediments richer in organic debris than the Cutler, such as the Chinle, and
was introduced into the fault zone and deposited, as open space fillings or
by replacement, during or after the time of faulting but at some time
preceding the introduction of uranium.
Much plant debris is plastic or liquid at seme time during the decomp¬
osition cycle, even through the bituminous coal stage. Van Krevelen and
Schuyer (1957, p. 275) report that small particles of bituminous coal flow
plastically under pressure at room temperature. The same writers (p. 73) also
state that "the hydrogen-rich maceral exinite...decomposes on heating into
a very plastic "melt" which, for the greater part, is distilled over as tar"*
It is probable that the plant debris was not coalified to the bituminous
stage at the time that it was subjected to the forces that redistributed
and deposited some of it in the fault zones in the Cane Creek area. It is
impossible to determine whether the present pyrobitumen was derived from
matter which was emplaced as a result of plastic flow, liquid flow, or
condensation from gaseous state. Whether the material deposited in the fault
could have at any time been called petroleum is of little significance.
- 18 -
Physical tests on the pyrobitumen as it exists today are given in a
later section. The organic matter Mas probably altered either continuously
or intermittently during and after mineralisation. The present pyrobitumen
is black and varies in composition. Its hardness varies inversely as the
degree of subdivision, and its luster varies from dull to bright. The
pyrobitumen forms stringers, lenses, veinlets, and irregular elongate masses
whose longest dimensions generally parallel the schistositv. Much of the
pyrobitumen polishes well, but other portions of the pyrobitumen are sooty
and do not polish and has variable, but generally low, reflectivity. Polished
sections show low, non-uniform reflectivity and anisotropism in various
shades of brown.
Post-fail) t. primary Minerals
Ankerite and calcite are the two earliest minerals to fill open spaces
in the faults. The sections that contain brown ankerite are likely to contain
calcite also. Both carbonates occur as cement and as veinlets, but inter¬
relations between the two were not observed. Ankerite is most ccaeon in the
vicinity of the carbonaceous material. Calcite was precipitated before,
during, and after ore, but all of the ankerite observed appears to be pre-
ore. Euhedral crystals of calcite were deposited as linings in open spaces
later filled with chalcopyrlte (fig. 6).
Following deposition of ankerite, barite (fig. 7) was precipitated in
the fault zone. Barite commonly occurs as radiating sheaves of blades -eplacing
organic matter and ankerite, and filling open spaces. Spectrographic analyses
(Table II) show a vague correlation of the percent of barium with that of
uranium, probably a result of the relation of both with the fault rather
than with each other.
The first ore element to be precipitated was vanadium which occurs in
montroseite and vanadium clay. Nontroseite is rare in the Honeybee mine
but is found in irregular masses in and near carbonaceous matter. It has
replaced mica in schist along cleavage planes (fig. 8). Direct age relations
of montroseite with uraninite were not observed, but montroseite is veined
by chalcopyrlte (fig. 8) which has overlapped the deposition of uraninite.
Vanadium clay corrodes and replaces nonvanadium clay and, in places,
detrital quartz and feldspar. The vanadium clay is light to dark red-brown
in thin section and has higher birefringence and coarser grain than the
vanadium-free clay which is probably detrital. Vanadium probably entered
the structure of the original clay during replacement and recrystallisation.
In addition to veins in montroseite, chalcopyrlte occurs as scattered
blebs and masses in the clay- and calcite-cemented sandstone and slltstone
portions of the fault-filling, and in the adjacent biotite schist (fig. 8).
It is finely disseminated in the pyrobitumen which contains uraninite
(fig. 9), and in calcite veinlets which cut the uraniferous pyrobitumen. It
veins the uraninite-organic intergrowt (fig. 10) and crackled uraninite
masses. The most common occurrence is as replacement of barite (fig. 7),
with growth originating along crystal faces and extending inward in all
gradations through complete replacement ss that in places pseudcmorptm of
chalcopyrlte after barite occur (fig. 11). Chalcopyrlte has also replaced
- 19 -
ankerlte in irregular masses and has filled in around calcite crystals which
were probably deposited in open spaces (fig. 6). It is probable that calcite
preceded the chalcopyrite here because calcite has such a low force of crystal¬
lization that it would not be likely to grow crystal faces against pre-existing
chalcopyrite.
Galena occurs principally as disseminated anhedral to subhedral crystals
in chalcopyrite (fig. 11). No satisfactory explanation for this intergrowth
has been found. Exsolution of galena from chalcopyrite seems unlikely,
although not impossible. Galena also is found as disseminated blebs in
pyrobitumen, in uraninite, and in calcite. Galena-bearing calcite veinlets
cut uraninite-pyrobitumen intergrowths.
Pyrite is a minor constituent of the ores of the Honeybee mine. It
occurs as small irregularly distributed anhedral masses cementing detrital
grains, in calcite which cements grains and veins pyrobitumen, and as blebs
in organic matter and schist. Rarely, it is found as replacement of chal¬
copyrite and barite.
The most abundant uranita mineral is uraninite which, most ccueonly,
forms blebs and veinlets in organic matter (fig. 9). In many sections the
uraninite-pyrobitumen Intergrowth is so fine-grained that the two substances
cannot be distinguished even under very high magnification. X-ray analyses
of this submicroscopic intergrowth show the presence of uraninite. There
are all gradations from nearly barren to highly uraniferous pyrobitumen.
Some uraninite veinlets are continuous from the pyrobitumen into the
adjacent biotite-quartm schist (fig. 12) and uraninite is disseminated as
patches in the schist, and cements sand grains in the unmetamorphosed sand¬
stone. It is always close to organic matter.
Figures 7, 11, and 13 show uraninite that has replaced barite and
chalcopyrite. Figure 14 illustrates the occurrence of uraninite as rounded
blebs in ankerlte and pyrobitumen. The shape of the uraninite grains may
be due to deposition in the colloidal state. In sandy portions uraninite
has replaced detrl.al mica along cleavage planes and has replaced quartz
in an Irregular pattern (fig. 10).
In one section chalcocite occurs as small anhedral crystals in chal¬
copyrite.
Qxldlud ■xntr&jg
The only uranium minerals found at the outcrop are secondary anderson-
ite and camotite. With increasing depth from the surface the amount of
oxidation decreases and uraninite becomes the predominant uranium mineral.
Oxidised minerals other than thoss of uranium include gypsum and "limonite"
which are common throughout the mine.
-20-
The following paragenetic sequence is proposed for the ore in the Honev-
Dwe mine: J
Quartz, clay, feldspar, detrital
■ica, detrital organic matter
Metamorphic mica
Redistributed organic matter
Ankerite
Barite
Vanadium clay and mica
Montroseite
Chalcopyrite
Chalcocite
Galena
Uraninite
Pyrite
Calcite
Secondary minerals (camotite,
andersonite, gypsum, limonite)
Early
The Honeybee No, 2 mine (fig. 4) is near th
in sec, 10, T. 27 S., R, 21 E, Mining has been
trending northwest and dipping steeply northeast
12 feet wide in the area mined (fig. 15).
Lithology
(fig. 4) is near the top of the Cutler formation
. Mining has been confined to a fault zone
g steeply northeast. The fault zone is up to
J f #4 _ S i- \ r
The unfaulted country rock in the vicinity of the mine consists mainly
of fine- to medium-grained, poorly sorted sandstone, mostly red in color, but
white in occasional thin layers and ccattered irregular patches. Some thin
layers of shale are interbedded with the sandstone. Principal detrital
constituents are angular to subangular grains of quarts, with feldspar and
varying amounts of mica. Accessories Include zircon, tourmaline, magnetite,
chert fra^ents, and fine-grained carbonaceous matter.
The cement is mainly calcite, although in some layers and in local
patches clay, fine-grained mica, hematite, and rock flour are more abundant.
♦ constltu ^«® »» -uct, as about 2 percent of the red rock whereas
the light-gray and white portions contain practically none. Most of the
contacts between the h«atitic and non-h«matitic portions are sharp.
Irregular, discontinuous patches of authigenic quarts cement up to a few
millimeters in diameter were observed in thin section.
.. ,, Except, for the presence of ore-minerals, the rock in the fault zone
differs very little from the surrounding country rock. Much arkosei is
interbedded with a little siltstone and mudstone. One thin bed of limestone
that contains rare quartz frajsents was observed.
Organic material
The concentration of organic matter appears to be greater in the mine
than in the country rock outside of it. This may be due to the fact that
the carbonaceous matter is very friable, eroding more easily than other rock
constituents, and therefore does not crop out. On the other hand, the organic
material may hare been introduced into the fault during or after the time of
faulting. The carbonaceous matter parallels original bedding planes rather
than fault planes and is more common in the finer sediments. It occurs in
angular discrete fra^ents resembling desiccated coal. Physical tests
performed on the organic material show that it is now a pyrobitumen. Generally
the pyrobitumen did not lend itself to polishing, but occasional fragments
that did polish show low reflectivity with anisotropism in shades of brown.
Unlike the pyrobitumenB from the other mines in the Cane Creek area,
that from the Honeybee No. 2 mine is only slightly radioactive. Moreover,
chemical and radiometric assays (Table 2) show that the material is
strongly out of equilibrium, with much higher eU 30 g than chemical U 30 g.
Post-fault mineralization and alteration
Traces of uraninite and chalcopyrite were found in one section of
pyrobitumen. However, most of the uranium in the Honeybee No. 2 mine is
present in secondary minerals, mainly boltwoodite and andersonite. Vhether
these were derived by oxidation of primary uraninite in the mine area or
whether the oxidized uranium was carried in from outside the immediate
vicinity is not known.
Other products of oxidation in the mine include limonite and stringers
and veinlets of gypsum.
Except for local irregular patches little hematite is present in the
vicinity of the fault where mining has taken place. At the inner end of
the mine tunnel, a good example of bleaching along fractures has been uncovered.
Here, the hematite-bearing rock has been fractured in several directions
with spacings between fractures of from $ to 10 inches. For about 2 to U
inches on either side of each fracture the rock is almost white, with only
remnants of red persisting farther away from the fractures (fig. 16).
Although in many places along Cane Creek it is not known whether the present
distribution of hematite is due to original deposition patterns or to
later removal of Iron in certain zones, it seems safe to assume that in the
Honeybee No. 2 mine the white zones are due to removal of hematite.
"B" prwrect
A short tunnel, called the "B" Prospect (fig. A)» located in sec. 10,
T. 27 S., R. 21 E., just below the Honeybee No. 2 mine, intersects the fault
in which the Honeybee No. 2 mine occurs. The faulted rock contains mostly
unaltered arkose and minor amounts of altered foliated rock. Foliation
parallels the fault and was probably produced by faulting. No uranium
minerals were observed in the mine or in the sections prepared from samplej
collected from it. Radioactivity in the tunnel is essentially the same as
the background for the area.
- 22 -
Table 2
Assay?
Sample SfiJ^Og
*eU 3 08
SV205
*Cu
%u
5fV
uA
U/Cu
1
17.23
15.28
1.74
0.01
14.20
0.975
14.6
103
2
1.41
1.18
0.91
0.06
1.16
0.51
2.3
2 x 10
3
1.17
1.17
0.24
0.02
0.96
0.13
7.4
5 x 10
4
11.70
11.07
1.16
0.71
9.64
0.650
14.8
14
5
0.01
0.31
0.20
Nil
0.008 0.11
0.07
—
6
0.28
0.44
0.38
0.02
0.23
0.21
1.1
10
7
0.02
0.23
—
—
0.016
—
—
—
8
14.33
15.15
6.73
—
11.81
3.77
3.13
—
9
5.77
5.71
0.06
Nil
4.76
0.03
2 x 102
—
10
56.35
32.38
0.43
Nil
46.45
0.24
19 x 10 2
11
29.38
25.08
0.54
0.01
24.22
0.30
81
2 x 103
12
1.59
2.19
1.33
0.44
1.31
0.745
1.76
3.0
13
1.83
2.10
1.46
0.14
1.50
0.818
1.83
1.1
14
14.91
13.74
8.42
0.40
12.29
4.72
2.60
31
15
31.91
27.37
3.02
0.07
26.30
1.69
15.6
4 x 10 2
16 20.28 18.93
— not determined
1.18
0.03
16.72
0.661
25.3
6 x 10 2
(1) Honeybee mine, ore In fault
(2) Honeybee Bine, ore in fault
(3) Honeybee nine, ore in fault
(4) Honeybee nine, ore in fault
(5) Honeybee No. 2 nine, carbonaceous material in fault
(6) Honeybee No. 2 mine, oxidised uranium ore at outcrop
(7) Honeybee No. 2 mine, carbonaceous material in fault
(8) Moneybee No. 2 mine, carbonaceous material and oxidised uranium ore in fault
(9) Moss Back adit, oxidised ore in fossil log at outcrop
(10) Moss Back adit, pyrobitumen surrounding fossil log in adit
(11) Moss Back adit, partly oxidised uraninite-bearing log
(12) Canary claim, andersonite ore in sandstone, in fault
(13) Canary claim, andersonite ore in sandstone, in fault
(14) Adair mine, sandstone ore
(1$) Climax School Section mine, ore from channel
(16) Climax School Section mine, ore from chanrel
- 23 -
Canary shaft
■
Mine workings on the Ca.^ry claim (fig. 4) consists of a pit approximately
20 feet deep in the same fault system as that of the Honeybee mine. The
Canary pit is in the Cutler formation on the north limb of the Cane Creek
anticline, northwest of the Honeybee mine. The rock is an arkose that contains
up to 10 percent mica and is cemented by clay and medium- to coarse-grained
calcite.
No primary uranium mineral w«»s observed, but it is quite probable that
deeper mining will expose primary uranium minerals. "Uranium minerals are
mainly andersonite which forms veinlets and coatings." Some of the clay cement
is vanadium-bearing.
A yellow uranium carbonate tentatively identified as sharpite, (U02)*,
(CO3)5(0H)2*7H2O(?), was found in one small sample. This mineral fluoresces
yellow under ultraviolet light. It occurs as very fine blades which have
parallel extinction, high birefringence, and pleochroism from pale yellow
to almost colorless. No interference figures could be obtained because of
the small size of the crystals, the indices determined are: jr (?) = 1.72
and ot. (?) - 1.63. These values are in good agreement with those given for
3 harpite by Palache, Berman, and Frondel (1951» p. 275), who give the
following optical properties for sharpite from Chinkolobwe, Belgian Congo:
Orientation n
X 1.633
Y 1 laths
Z elong. r~j 1.72
pleochroism
brownish
biaxial (/)
yellowish green
According to Frondel, Riska, and Frondel (1956), authentic X-ray data on
sharpite are lacking. The following d-spacings were measured for the Cane
Creek material:
d (A)
8.1
7.5
7.0
4.05
3.71
3.50
3.12
2.85
Intensity
VS
W
M
S
M
W
W
w
Mfflns.fcine 'aim
VS very strong, S strong,
M medium, W weak
No radioactivity was detected and no uranium minerals observed on the
Moonshine claim (fig. 4). Several prospect pits have Deen dug along a
minor northwest-trending, northeast-dipping fault in the Cutler arkose.
Thin coatings of malachite occur on fracture surfaces.
- 24 -
Red Zero claim
A small amount of uranium was found in the Red Zero claim (fig* U) in
the Moenkopi formation. Host rocks are limy, mudstone-pellet conglomerate
and sandstone, and argillaceous limestone containing scattered mudstone
pellets. The ore is in a faulted area and was observed only in irregular
pockets a few feet across, although several exploratory drifts have been
excavated. Uranium is present mostly as carnotite which coats detrital
grains, particularly mudstone pellets. More rarely, it occurs as uraninite
in small carbonaceous pellets and coalified wood fragments. Gypsum and
limonite are abundant as coatings on fissure walls and in fossil wood.
"Moss Back adit"
On the east side of the canyon uranium minerals occur in the Moss Back
member of the Chinle formation as replacement of organic matter, mainly
in large logs which have been coalified. The logs are in the sandstone near the
extension of the fault found at the Honeybee mine. Most of the faulted rock
had been eroded from the area in which the uranium occurs in the Moss Back.
High grade coalified logs have been selectively mined at the outcrop. A
short adit, called the "Moss Back adit", has also been driven. Here, other
mineralized logs were uncovered.
Lithology
In the vicinity of the mineralized logs the country rock consists of
interbedded calcite-cemented sandstone, calcareous siltstone, and both pure
and argillaceous limestone. The detrital grains in the sandstone are mainly
quartz with minor feldspar and accessory mica, zircon, chalcedony, and
magnetite. In a few layers, however, many or most of the grains are limestone.
Late calcite veinlets up to 1.5 mm. thick cut the rock in places, and
calcite scalenohedrons up to an inch wide, many intergrown with celestite
blades up to an inch or more in length, have formed in fissures and other
open spaces. Celestite cements detrital grains. Megascopically the calcite
is white to pink and the celestite is mottled white, pink to peach, or pale
yellow-green.
Organic material
Much of the cellular texture of the coalified wood has been retained where
it has been replaced by mineral constituents (fig. 17), but no cell structure
was observed in unmineralized coalified wood.
A 1-inch layer of non-cellular uraniferous organic material was found
adjacent to one of the logs in the adit. This pyrobitumen as probably
derived from the fossil wood during seme phase of alteration prior to
uranium mineralization. Some of the physical properties of this pyrobitumen
are given in Table 3* After mineralization there was additional redist-ibution
of organic material into shrinkage cracks in uraninite (fig. 18).
In addition to the mineralized carbonaceous matter, many small non-
mineralized fragments are scattered through the rock in the vicinity of the
- 25 -
Moss Back adit. In polished section most of the organic material, whether
uraniferous or non-uraniferous, is anisotropic in varying degrees, with
interference colors in shades of brown.
Uranium and associated minerals
Uraninite has replaced various portions of the fossil wood and other
pyrobitumen. At different places within a single log it has replaced cell
centers (fig. 19) and cell walls (fig. 17). The cell texture may be clearly
defined or distorted and nearly or completely destroyed. In the pyrobitumen
at the margin of the log in the adit, uraninite occurs as tiny disseminated
blebs.
Pyrite also has preserved the cell structure of wood while replacing
it in varying degrees (fig. 20). In places it has replaced all parts of
the fossil wood except for an outline of the cells consisting of carbon¬
aceous matter or calcite. Elsewhere it has replaced only the lumens or only
the cell walls. Other occurrences of pyrite include cubes and irregular
masses in uraninite. Blebs of pyrite occur in late calcite veinlets in
the organic matter outside the fossil log. Veinlets of solid pyrite cut
earlier pyrite which has replaced cells. Stringers of cubes and blebs of
pyrite alternate with calcite along scalenohedral faces (fig. 21). Pyrite
has formed arborescent skeletal crystals in calcite (fig. 22). In a peculiar
orbicular intergrowth of pyrite with calcite (fig. 23 ), the orbs seem much
too large to have been formed by replacement of individual wood cells.
Rarely pyrite cements sandstone outside the logs.
Marcasite has precipitated alternately with calcite in the same manner
as pyrite (fig. 24), but the crystals are needles rather than cubes.
Marcasite also occurs as rounded or irregularly shaped masses in calcite.
Minor amounts of chalcopyrite occur as cement in sandstone.
Calcite has replaced most of the organic matter of fossil wood not
replaced by metallic minerals. Some calcite was precipitated alternately
with pyrite and marcasite. Calcite veins massive pyrite and marcasite and
has Replaced pyrite cubes. Where uraninite occupies cell walls, calcite has
filled the lumens (fig. 17); conversely where uraninite occupies the lumens,
calcite has replaced cell walls (fig. 19). Calcite veins massive uraninite
and uranlnite-organic intergrowths.
Oxidation
The mineralized logs have been altered by recent weathering so that the
uraninite has been oxidized and secondary uranium minerals have formed as
veinlets and coatings in and near the fossil logs. The secondary uranium
minerals include beta-zippeite, andersonite, boltwoodite, and rarely, an
orange yellow mineral tentatively identified as masuyite, U 03 * 2 H 20 .
Optical properties of this masuyite, as compared to data given for
masuyite by Frondel (1956, p. 563), ares
- 26 -
Masuyite (Frondel)
Cane Creek mineral (Corey)
oc 1.785 pale yellow
jB 1.906 deep golden
t 1.917 deep golden
1.765 colorless
1.882 yellow
1.887 yellow
Orthorhombic, (-)
2V = 50®
X perpendicular to cleavage
Biaxial (-)
2V = 0 - 10°
X perpendicular to cleavage
The d-spacings for masuyite from Katanga, Belgian Congo, Frondel,
Riska, and Frondel (1956) and for that from Cane Creek are:
Katanga Cane Creek
0
d-spacings (A)
Intensity
0
d-spacings (A)
Intensity
8.53
1
7.10
10
7.2
VS
6.8
W
6.43
6.6
w
2
6.3
w
5.7
vw
4.80
1
4.35
4
4.4
vw
3.92
2
3.54
8
3.58
s
3.53
s
3.15
9
3.17
s
2.97
1
2.94
w
2.74
3
2.80
w
2.51
5
2.51
M
2.38
2
2.38
w
2.06
1
2 .oe
w
1.984
6
1.97
M
Frondel (1956, p. 554) states that "the X-ray pattern of masuyite is
virtually identical with that of vandendriesscbefcte", (Pb 0 » 7 U 03 * 12 H 20 (?) ).
Since no lead was detected in the Cane Creek material and since the optical
properties are very near to those given for masuyite, the mineral is
tentatively called masuyite. However, Frondel, Riska, and Frondel (1956,
Ri 1^*3) states ft There is also a more or less close resemblance in pattern
lot fourmarierite, Pb0*4U03<>7H20(?)_7 to vandendriesscheite, masuyite,
and schoepite ( 2 U 03 « 5 H 20 ), and these minerals are at least closely related
in structure — if indeed, a continuous series does not extend between
them. The patterns of all of these minerals are distinguished by a pair
of very dark lines with d = 3.4-3.6 and d = 3.0 - 3.2". The pattern of
the Cane Creek mineral shows 2 strong lines in the 3.4 - 3.6 range and may
be of seme intermediate composition, possibly containing slightly more
water than masuyite.
Much of the pyrite has been oxidized, with subsequent formation of
hematite, limonite, and gypsum. Hematite with metallic luster has formed
pseudomorphs afta-pyrite. Whereas powdery red hematite occurs disseminated
- 27 -
throughout, the logs and surrounding rocks. Gypsum veinlets occur in
mineralized logs and in the sandstone.
Kaolinite stringers and veinlets up to 0.5 inch across, probably derived
from alteration of feldspar, are found in the sandstone surrounding the
mineralized fossil wood.
Paragenesis
The following paragenesis is suggested:
Early Late
Detrital minerals -
Calcite ————
Celestits ———
Uraninite -
Pyrite — —
Marcasite -
Redistributed organic matter -
Oxidation products (hematite, etc.) ~ -
Adair mine
Uranium ore in the Ada^. mine, sec. 32, T. 26 S., R. 21 E., Grand
County, occurs in the Moss Back member of the Chtnle formation. The ore
which is in sandy carbonaceous lenses in a shallow channel, was mined by
stoping on either side of a 150-foot, northwest-trending adit.
Lithology
The host rock is calcite-cemented sandstone, generally medium-grained,
which; on either side of the ore grades into calcareous siltstone interbedded
with limestone, shale, and minor sandy layers. The sandstone contains a
large percentage of argillaceous limestone pebbles (fig. 25) and is locally
conglomeratic, containing limestone pebbles up to 15 millimeters in diameter
(fig. 26). Other detritals are quartz, feldspar, mica, chert fragments,
fossil wood, and accessory zircon, magnetite, and tourmaline. In sene silty
layers mica is a major constituent, producing fissility parallel to the
bedding planes.
In the vicinity of the ore calcite is the main nonmetallic cementing
agent. Farther from the ore hematite is locally abundant in the siltstone
layers, imparting a bright rusty color to the rock. Hematite was not
observed in or near the ore.
Organic material
Altered woody matter is connon throughout the mine. In places the
organic material has been entirely replaced by various minerals (fig. 27)
and in others the wood h? been coalified and only partly mineralized (fig. 28).
Optically the pyro'uitume anisotropic with brown interference colors.
Some of the physical properties of the pyrobitumen are discussed in a
following section. In addition to the residual carbonaceous matter remaining
- 28 -
in its original position, small amounts of liquid or plastic organic matter
flowed into cracks in the coalified wood at some time after introduction
of uranium.
Uranium and associated minerals
Uranium is present mainly as uraninite which has commonly replaced the
cell walls of fossil wood (fig. 27) with calcite occupying the lumens.
Occasionally only a ring of uraninite remains with calcite occupying the
inner layers of the cell walls as well as the lumens (fig. 29). Elsewhere
uraninite has replaced all parts of the wood indiscriminately. Possibly the
cell texture was destroyed before the introduction of the metallic minerals.
Uraninite cements detrital grains (fig. 30) and has replaced parts of grains
of impure limestone (figs. 26, 30 ).
Vanadium minerals present are vanadium clay and montroseite. The
fine-grained brown vanadium clay cements sand grains near carbonaceous
matter, and montroseite occurs as needles and fibrous intergrowths that
cement sand grains at the margins of fossil wood fragments. In polished
section the intergrowths of ecicular crystals appear massive in ordinary
light, but under crossed niuuls the anisotropism of the montroseite needier
shows the structure clearly. Montroseite has replaced mica along cleavage
planes (fig. 21) but otherwise commonly occurs in interstices (fig. 26).
Pyrite is more abundant in fossil wood which has not been entirely
mineralized than in the completely mineralized wood. In the coalified wood
it appears as masses in sections where cell texture has been destroyed.
Where uraninite has replaced the cell walls (fig. 32), pyrite cubes, now
surrounded and partially corroded by uraninite, may nave grown from lumens.
Pyrite veins in massive uraninite were probably formed by filling shrinkage
cracks in the uraninite. Coalified wood containing minute blebs of pyrite
is cut by some late calcite veins that contain pyrite (fig. 28). In
sections where cellular matter has been entirely mineralized, pyrite has
replaced many cell walls (fig. 27). Pyrite is rare outside foss41 wood,
but does cement some sand grains. *
Marcasite is relatively rare and is found as irregular blebs in fossil
wood and in sandstone.
Chalcopyrite has replaced walls of cells (fig. 29) and is found as
anhedral crystals in calcite in fossil wood. It has also partly replaced
feldspar grains in the sandstone (fig. 30),
Galena occurs as minute blebs in uraninite in fossil wood and as
anhedral to subhedral crystals in calcite (fig. 33)» It also occurs with
uraninite in the sandstone cement.
Calcite was present in the original sediments as limestone beds and
as limestone grains in the sandstone. More calcite may have been introduced
to form the calcite cement, or this cement may have been produced by
recrystallization of calcite already present. Much of the calcite was
recrystallized or emplaced after the formation of the metallic minerals.
- 29 -
In fossil wood calcits has filled lumen; in portions where the cell walls
are uraninite, pyrite, or chalcopyrite (figs. 27, 29), and veinlets of calcite
cut across pyrite and uraninite (figs. 32, 28).
Barite is rare and occurs as red euhedral blades In calcite which has
veined the fossil wood.
O^fj-1.20
Oxidation of the minerals of the ore sane has resulted in the format ion
of camotite on the outcrop and of thenardite (Na^SQt,) as a fluffy white
coating in places on the mine walls.
Parayenesls
The paragenetic sequence appears to be:
Early Late
Detrital fragments -
Calcite I, i - i ■.
Uraninite -
Chalcopyrite ?_?
Pyrite -
Marcaslte -
hontroseit# T —— T
Galena ■
Redistributed organic matter ——
Oxidation products ■
CUmk Swum aln?
The Climax Uranium Company mine on the school section, 32, T. 26 S.,
R. 21 E., Grand County, is in the Moss Back member of the Chinle formation.
The uranium ore is closely associated with plant remains which were deposited
in a shallow northwest-trending channel. The channel filling is mostly
green shale up to 4 feet thick with scattered lenses and thin beds of sand¬
stone and siltstone. Two systems of fractures, one trending N. 15® W.and
dipping steeply northeast, and a second trending N. 25® E. and dipping
steeply southeast intersect the channel. Small, lens-shaped, high-grade,
uraninite-bearing ore bodies occur where the northwest-striking fractures
intersect sandy, carbonaceous pockets in the channel. In addition to the
pods of uraninite-bearing ore, stringers and coatings of secondary uranium
minerals occur paralleling the bedding planes and the fracture planes.
The adit trends approximately east, and drifts on either side have
followed the channel where it was intersected approximately 35 feet east of
the portal. The main adit has been continued seme 150 feet beyond the
channel (October, 1957) but the green layers become barren east of the
channel, and no more ore was encountered. Drilling from the top of the
mesa has indicated ore approximately 35 to 40 feet east of the adit heading.
Further development may disclose the relationships of ore, fracturing,
and channel structure.
- 30 -
Lithology and orqn;c material
The rock lMmdiatelj below the ore-bearing shale ia a pink to gray,
fine-grained sandstone containing major quarts, minor feldspar, and accessory
mica, slr:on, tourmaline, and magnetite. Tha cotm la mostly clay and
aorlclto with son calclta and hematite. Tha pink color of tha rock la
dua to a thin coating of hematite around many o» tha grains and to grains
which hara been partially replaced by hoaatlto. Many of tha fn^en*. a of
fa Ids par and nica contain ya ini at a of hsatlte along cleavage pianos. Tha
sandstona gradas upward into shala, and a sona about a foot thick is of
intarbaddad layers of pink sandstona and grasn shala.
Tha emplacement of ora was controlled by tha localisation of woouv
aattar in pods in the green shala-sandstone channel filling. At tha presort
tins, vary littia carbonaceous natter is visible either aegascoplcally or
skicroecopically in the ore lenses. However, tha call texture has baan
preserved where tha organic natter was replaced by air.eral s. Tha woody
fra^aents vary in *ise from a millimeter to several centimeters. These
fragments ware deposited with sand in lenses up to 2 feat thick and 3 or
4 feat in the other two linens ions. Tha sandy lenses grade outimrd into
green shale.
Above tha shala layer is a fine-grained, clay-canonted, white sandstone
containing major quarts and coallfled wood fra^ents, ninor feldspar, and
accessory nica. The pieces of fossil wood have been flattened parallel
to the bedding, and bent and twisted in other dimensions. In the plane
paralleling the bedding tne fragments are up to 5 inches across but they
do not exceed 0.) inch in tnickness. All of the carbonaceous natter in
the white sandstone is barren. Except for the fra^aents of fossil wood,
the sandstone is very well-sorted and has little pcre space.
Uranium and associated minerals
The principal uranium mineral in the Climax mine is uraninite which
replaces parts of the woody fraptents and cements, and replaces (figs. 34, 35)
the sandstorm surrounding the wood. As the sandstone grades Into shale
uraninite becomes scarcer and store disseminated and finally is completely
absent. Probably the porosity of the sand permitted freer passage of
uranium-bearing solutions than did the finer-grained sediments. The abundant
organic matter was at least partly responsible for the reduction and pre¬
cipitation of uranium.
The cell texture of the wood has been preserved to varying degrees
where uraninite has replaced cell walls (fig. 6). In some sections uraninite
has replaced carbonaceous matter almost completely (Pig. 37) with only
faint remnants of cell structure remaining. The most ccomon occurrence of
uraninite in replaced wood is as tiny rounded blebs in calclte (fig. 38).
The relation of these minute blebs to the original plant structure is not
known. They are seen in longitudinal sections of the fossil wood, and the
same sections contain solid masses and stringers of uraninite.
Uraninite occurring along crystal faces in calcite was either deposited
alternately with calcite (fig. 39) or else it penetrated along crystal faces
of previously existing calcite (fig. 40). Alternating layers of uraninite
- 31 -
and calcite shown in figure 39 suggest open space filling. Pyrite crystals
were deposited first, followed by uranlnite and calcite precipitated alter¬
nately. Late calcite penetrated along the boundary between pyrite and
uranlnite, corroding the pyrite.
Plgure 41 shows a crystal of pyrite which was veined by uranlnite and
subsequently partly replaced by calcite which did not replace the uranlnite.
Also shown are reanants of longitudinal sections of wood cells in which the
uranlnite outlines the cell walls.
In a few fragaents of fossil wood, pyrite fills the lumens, and calcite
or uranlnite replaces the cell walls. Irregular patches and subhedral
crystals of pyrite are scattered throughout replaced wood. Pyrite occurs
as anhedral to subhedral crackled masses which were probably deposited as
open space fillings (fig. 39). Hany cracks are filled by uranlnite and
calcite.
In places sand grains are cemented wholly or in part by pyrite. In
sections where pyrite, along with uranlnite and calcite, is the cement
the pyrite generally occurs as subhedral to euhedral crystals or rounded
anhedral masses adjacent to the detritals and is rimed by uraninite, with
calcite filling the remaining space between grains. Rarely, pyrite occurs
at the interface between uraninite and calcite or crystals occur disseminated
in uranlnite. Pyrite crystals have penetrated detritals, but extensive
replacement of detritals is rare. A few euhedral pyrite crystals have
replaced uraninite lfig. 42). Pyrite also occurs in velnlets of late calcite
that cut massive uraninite.
Galena is quantitatively unimportant, but it is scattered throughout
all sections that contain uraninite; its commonest occurrence is as small
anhedral to euhedral crystals disseminated in uraninite (fig. 43). It
is also found in calcite that replaces wood or cements detritals. Rarely
galena has replaced parts of detrital grains; a few masses and crystals
of galena are as much as 1 millimeter in greatest dimension, but most are
much smaller.
Copper minerals are rare and were found only in the sections of replaced
fossil wood. Chalcopynte, the most abundant of the copper minerals, occurs
mainly as eunedral to anhedral crystals disseminated in calcite (fig. 35),
and it has partly replaced galena in some sections. Bomite is very rare
and is found as blebs disseminated in calcite and as partial replacement
of chalcopyrlte. Both chalcopyrite and bornite have been partially oxidized
with subsequent formation of covelllte in veinlets through the other copper
minerals and in nearby uraninite (fig. 44).
Laths and rounded masses of specular hematite were also found in
calcite-replaced fossil wood. No paragenetic relations to other metallic
minerals were observed.
Vanadium appears to be concentrated in vanadium clay in the outer
portions of the sandy pods. No montroseite was observed; however, it may
well be present considering the similarity of the mineralogy of the Climax
mine to that of the Adair mine in which montroseite was found, and in consider¬
ation of the vanadium content of the high grade, low clay portions of the
ore assayed (table 2).
- 32 -
Calcite is the most Conor, nonmetallic cementing material in the
1—wdiate vicinity of the ore, artd it has replaced many parts of fossil
wood. Cell texture has been retained only where uraninite has replaced
cell walls and other parts of the cell structure (fig. 36). The calcite which
encloses uraninite is fairly coarse-grained and appears black Decause of
the included uraninite whereas barren calcite is also coarsely-crystalline,
but trtilte. Even where the two varieties are in contact, each crystal is
always either white and barren, or black and uraniferous.
Calcite is most abundant in the sandy lenses where uranium is concen¬
trated. This is probably due to the fact that these portions were more
permeable, with pore spaces not already occupied by rock flour and clay.
Calcite, along with uraninite and pyrite, cements detrltal grains. As the
sediment becomes finer-grained toward the edges of the lenses, calcite
bee ernes scarcer, although some is present in the shale and siltstone as
irregular, scattered patches. No limestone pellets were observed in the
sandstone although calcite has partly replaced many of the detrltal grains.
Red, euhedral blades of barite were found in calcite-replaced wood.
The barite crystals are fresh and uncorroded and were probably precipitated
at about the same time as the enclosing calcite. No relationship to minerals
other than calcite was observed.
In one section several velnlets of colorless chalcedony in sandstone
were observed.
Oxidation
Oxidation of the CliJ&ax ore has resulted in the formation of beta-
zippeite (figs. 45# 46, 47), andersonite, and boltwoodite. All ore mined
to date (October, 1957) contains at least small amounts of secondary uranium
minerals. All three occur intimately associated with gypsum, but not with
each other. Beta-zlppeite and andersonite are found as stringers and veinlets
parallel to the bedding and along nearly vertical fracture planes. Beta-
zippeite is more abundant and is more common in sandy zones, but andersonite
is more common in siltstone and shale. Boltwoodite is rare and is found as
veinlets in sandstone.
Gypsum is common throughout the sandstone lenses, and, in places, it
cements detrital grains. It also occurs as veinlets in sandstone with and
without the secondary uranium minerals.
Fine-grained red hematite is scattered throughout the rock, particularly
in the sandy parts, where it has coated and replaced many of the grains.
Paragenesis
The positions of some of the minerals in the paragene ic sequence is
quite obvious, but conflicting evidence, or lack of evidence, leaves the
positions of others in doubt. In most instances pyrite appears to have
been precipitated before uraninite (figs. 41, 44, 39). It appears most likely,
however, that the pyrite crystals shown in figure 38 developed after the
uraninite because the texture of the uraninite, inherited from fossil wood.
- 33 -
continues uninterrupted through tf»e pjrrite crystel. Pjrrite sho»«> In Figure 42
ties replaced uraninite. Either there were two generation* of pyrite, or
deposition of pyrite and uraninite overlapped.
The paragenetlc relation of galena is generally indeterminable, although
a few veinlets of galena cut uraninite (fig. 40).
Calcite must have preceded uraninite in seme sections since uraninite
follows the crystal outlines of calcite (fig. 40). It is very likely that
this texture is a result of alternating precipitation of uraninite and calcite.
Veinlets of calcite cut across uraninite which has replaced cells (fig. 36).
In sandy portions calcite has filled open spaces left after uraninite ringed
or replaced the grains (fig. 34).
Relative ages of chalcopyrite and bomite to uraninite and pyrite were
determined indirectly. Bomite has replaced chalcopyrite which in turn
has replaced galena. At least some of the galena was deposited later than
uraninite and uraninite later than some pyrite, so that chalcopyrite and
bomite are probably later in the sequence than uraninite and pyrite.
Covelllte, probably an alteration product of bomite and chalcopyrite, veins
these two minerals and uraninite. However, Intervening calcite contains no
covelllte.
The above observations have led to the following paragenetlc sequence
for the ore of the Climax School Section mines
Early
Detritals —
Calcite
Barite -
Vanadium clay ?——?
Pyrite
Uraninite
Galena
Chalcopyrite
Bomite
Covelllte
Oxidation products
CHEMICAL AND RADIOMETRIC ANALYSES OF ORE
The samples assayed chemically and radiometric\lly (Table 2) were
chosen either because they were representative of the typical high-grade ore
studied in polished and thin sections or because tre results could be used to
estimate the state of equilibrium or disequilibrium of the ore. Probably
none of the samples represents the average ore of any mine.
Generally the amount of uranium exceeds that of vanadium, but U/V ratio
is highly variable. It is noteworthy that the U/V ratio for ore from the
Moss Back member on the east side of the car.yon is as much as 100 times greater
than that for ore from the Moss Back on the west side. In general the
uranium-vanadium ratio is reflected in the secondary uranium minerals present.
Camotite was observed in the Honeybee, Honeybee No. 2, and Adair mines
whereas none was found in the Moss Back adit nor the Climax School Section
mine. An Anomalous situation exists in the pit on the Canary claim where
no camotits was observed, although the UA ratio is low. The common uranium
secondary mineral is andersonite. Either the uranium in this area was oxidised
and formed secondary minerals while the vanadium remained unoxidised, or
else the oxidised uranium was introduced from some outside source.
Most of the samples are not in radiometric equilibrium. Host of the
unoxldlzed or partly oxidised ores are low radiometrlcally while the oxidised
ores are high radiometrlcally.
The uranium copper ratio is extremely variable because the copper contmit
remains small while the uranium content varies from sample to sample.
PHYSICAL CHARACTERISTIC OF THE ORGANIC MATERIAL
Organic matter from four of the Cane Creek mines was isolated by hand
picking under a binocular microscope.
Results of physical tests on the samples described below are given in
Table 3*
(1) Honeybee mine: Black lenses and layers in blotlte schist. Mostly
massive, black, hard, dull, rarely harder and shiny. Much uraninlte,
chalcopyrite; minor pyrite, galena and gangue minerals.
(2) Honeybee mine: Thick velnlet of solid black. Mostly dull, hard,
but includes velnlets of shiny black. Much uraninlte; minor chalcopyrite,
calcite, galena, pyrite.
(3) Honeybee mine: Brownish-black material disseminated in biotite
schist. More altered and less pure than (1). Soft, dull. Some andersonite,
uraninlte, chalcopyrite, gangue.
(4) Honeybee No. 2 mine: Black; from friable, poorly cemented sand¬
stone in fault zone. Soft, brittle, shiny. Contains a few detrltal grains.
(5) Adair mine: Coallfied wood. Hard, brittle, dull. Minor calcite,
pyrite, uraninlte.
(6) Moss Back adit* Black material at edge of log. No woody texture
remains in material sampled. Hard, dull. Much uraninlte; minor pyrite,
galena.
Testing procedures
The following tests were performed on the samples described above:
I. A. Samples dried at 140° for one hour. Cooled and weighed.
Bo Remainder allowed to stand in CS 2 for 72 hours. Filtered, washed
with CS 2 , dried, and weighed.
- 35 -
-? 6 -
Table 3
RESULTS OF PHYSICAL TESTS ON PYKOBITUMBI
i<_ ii ni
Sample
U
$B
$c
U
*B
$c
to
A
B
(1)
2.41
nil*
12.40
1.88
66.91
10.29
a.oi
Does not bum
nor fuse
Bums with red glow.
Infusible#
(2)
2.62
nil*
a.79
1.83
74.19
22.17
1.81
Bums with red
glow. Infusible#
Bums with red glow.
Infusible
(3)
10.35
nil*
29.16
7.27
49.74
24.51
18.44
Bums with red
glow. Infusible#
Bums with red glow.
Infusible
(4)
12.88
nil*
44.94
10.08
30.77
32.72
26.42
Bums with red
glow. Infusible#
bums with red glow.
Infusible
(5)
1.89
3.00
83.32
1.66
2.51**97.00
1.34
Bums with smoky
yellow flame.
Infusible#
Bums with smoky yellow
-flame. Infusible
(6)
5.17
nil*
25.87
3.45
77.56
18.44
0.45
Bums with red
glow. Infusible#
Bums with red glow.
Infusible.
, See text for detailed explanation of tests and properties.
* Less than 0.01$
** - % increase in weight.
# Material does not support combustion outside of flame.
C. Residua from B ignited at 810° C. for one hour.
II. A. Samples dried at 110° C. for one hour. Weighed
B. Boiled in 1:3 *0^ for one hour. Filtered, washed, dried, and
weighed.
C. Ignited at 810° C. for one hour. Weighed.
III. A. Fragment placed in alcohol flame for one minute.
B. Fragment placed in b 1 >wtorch for one minute.
Procedure I Calculations and results
A. Weight loss at 110° C. X 100 = % loss at 140° C.
Weight of original sample
Remarks* Results were always higher than loss at 110° C. due to loss of
additional water (such as water of crystallisation of one or more minerals),
loss of volatile organic constituents, and/or loss of C0 2 from partial
decomposition of carbonates.
Weight of original sample
= % dissolved in
CS 2
c. Weight of residue from a - weight of residue from C x 100 = % loss on
Weight of original sample ignition
Remarks: Difference between this and II-C is probably due to presence of
uraninite and sulfides that were oxidised, causing increase in weight, and
to the presence of carbonates that partially or wholly decomposed, causing
decrease. Therefore, this determination has little meaning without determin¬
ation of the amount of original uraninite, sulfides, and carbonate.
Procedure II
A. Loss m weight_ X 100 = % of adsorbed water.
Weight of original sample
Remarks: Sample preparations and tests were carried out during damp weather.
B. Weight of residue from A - wei ght of residue from B x 100 - % dissolved
Weight of original sample in 1*3 HJ 03
Remarks: Loss consists of carbonates (mainly calcite, ankerite, and
andersonite), uraninite, and sulfides (mainly pyrite, marcasite, galena,
and chalcopyrite). Some organic material may have dissolved. One sample
increased in weight, probably due to the formation of organic nitrates;
other samples may have reacted similarly, but the increase was more than
offset by the loss by solution of other constituents.
C. Weight of residue from fa - weigh t of residue from C x 100 = % loss on
Weight of original sample ignition
Remarks: Indicates approximate percentage of organic constituents.
D. We ight of residue fron C x 100 = % ash
Weight of original sample
Remarks: Consists of quartz, feldspar, mica, clay, barite, etc.
Procedure III
A. and B. Indicates whether material fuses and/or burns in the respective
flames and whether the material supports combustion.
Discussion
The organic materials found in the various Cane Creek mines are all
pyrobitumens according to Abraham’s classification (Abraham, 1945). According
to this classification pyrobitumens are "native substances of dark color;
comparatively hard and non-volatile; composed of hydrocarbons, which may or
may not contain oxygenated bodies; sometimes associated with mineral matter,
the non-mineral constituents being infusible and relatively insoluble in
carbon disulfide. Scope: 'his definition Includes the asphaltic pyrobitumens
(elaterite, wurtzilite, albertite, and impsonite), also the non-asphaltic
pyrobitumens (peat, lignite, bituminous coal and anthracite coal), and their
respective shales." All of the samples tested from Cane Creek are infusible,
and only one is even slightly soluble in carbon disulfide. The distinction
between asphaltic pyrobitumen and non-asphaltic pyrobitumen is more difficult
to make since the oxygen content is generally determined by difference after
determination of hydrogen, carbon, nitrogen, sulfur, water, and ash; and
most of these were not determined on the Cane Creek materials. The coalified
wood from the Adair mine is obviously non-asphaltic. The tested material
from the Moss Back adit came from a 1- to 2-inch layer surrounding a large
fossil log and was undoubtedly derived frcsn the log. Lack of cell structure
is no criterion whatsoever since many fossil plant-remains show no remnants
of cells. The remaining samples, therefore, may be asphaltic or non-asphaltic
pyrobitumens although they closely resemble the non-asphaltic material from
the Moss Back adit. It is the opinion of the writer that most, if not all,
of the organic material is the product of alteration and redistribution of
organic matter deposited in the original sediments. During the processes
of burial, compaction, folding, and faulting, metamorphosis of the organic
detrital matter took place, resulting in many different chemical-physical
changes including loss of volatile constituents, carbonization, polymerization,
distillation and condensation, and plabtic- and liquid-state flow. In any
case, the end result is the production of the present pyrobitumens, The
term "asphaltite" which has been used to describe some of the substances
tested is an incorrect one according to Abraham’s classification.
COLOR DIFFERENCES IN THE CUTLER FORMATION
The various differences in color of the Cutler formation in and near
the Honeybee and Honeybee No. 2 mines were studied by means of thin section,
quantitative chemical analyses, and semi-quantitative spectrographic analyses.
The chemical and spectrographic analyses are given in Table 4. The samples
selected for analysis were collected from the fault zone and from rocks about
75 feet away from the fault.
The term "unbleached rock" is used in this paper to mean rock that is
some shade of red, and "bleached rock" refers to rock that is lighter in
-38-
A
Table 4
Chemical and Spectrographic Analyses of "Bleached" and "Unbleached"
Cutler rock
Chemical*
(1)
(2)
(3)
(4)
(5)
(6)
$Fe(IIl)
1.05
2.01
1.67
3.38
6.31
21.42
% Fe(II)
0.04
0.06
0.36
0.15
0.98
1.09
jaectrographic#
Si
M
M
M
M
M
M
A1
7.
7.
7.
7.
M
7.
Fe
.7
1.5
.7
1.5
1.5
7.
Mg
.7
1.5
3.
1.5
1.5
1.5
Ca
.7
.7
7.
M
.3
.7
Na
1.5
1.5
3.
3.
1.5
1.5
K
3.
3.
3.
3.
7.
7.
Ti
.15
.15
.03
.15
.3
.3
Mn
.015
.07
.03
.03
.03
B
tr
0
0
Ba
.07
.07
.07
.07
.03
.03
Be
0
0
0
MJJEl
Co
0
0
M/I
Cr
Cu
.003
Ga
.0007
.0007
.0007
.0007
.0015
.0015
Ge
0
0
0
0
0
<.005
La
0
0
0
0
0.003
.003
Mo
0
0
0
0
.0007
.0007
Nb
tr
tr
0
0
.0015
.0015
Nd
0
0
0
0
tr
tr
Ni
.007
rTTTJ
Pb
0
Sc
0
Sr
.015
.015
.03
.03
.03
.03
U
0
0
0
0
.15
.7
V
.07
.15
Y
0
Yb
mjVI
-
-
Zr
__
*015
.03
.03_
Figures are reported to the nearest number in the series 7, 3, 1.5, 0.7,
0.3 etc. Sixty percent of the reported results may be expected to agree with
the results of quantitative methods.
Symbols used are: not looked for; 0: looked for but not detected; Ms major
constituent, greater than 10$; trs near threshold amount of element.
Looked for, but not detecteds P, Ag, As, Au, Bi, Cd, Ce, Dy, Er, Eu, Gd, Hf,
Hg, Ho, In, Ir, Li, Lu, Os, Pr, Pt, Re, Rh, Ru, Sb, Sn, Sm, Ta, Tb, Te,
Th, Tl, Tm, W, Zn.
* by Brown Laboratories, Grand Junction, Colorado
# by U. S. Geological Survey, Denver Laboratory, reported in TDS-8776 and
TD3-880C.
(1) Honeybee No. 2 mine, white sandstone along fractures at end of adit.
(2) Red sandstone associated with (1).
(3) White Cutler arkose from outcrop, 40 feet south of Honeybee No. 2 mine.
(4) Red Cutler arkose associated with (3).
(5) Honeybee mine, green biotite schist in fault.
(6) Red biotite schist associated with (5).
color, typically white, light-gray, or green. Bleached rock in the Cutler
formation and in other formations in Cane Springs Canyon is widespread and
is by no means confined to the ore zones.
In each of the three pairs of rock analyzed, the red (unbleached) and
white or green (bleached) rocks were in patches a few tenths of an inch to
a few inches apart. The bleached and unbleached portions were carefully
hand-separated and ground.
The quantitative analyses show that the change from red color to a
lighter color was caused chiefly by removal of Fe(IIl) which was present
as hematite. The possibility of reduction to Fe(Il) with the Fe(II) remaining
in the rock was considered, but the analyses show that the amount of Fe(Il)
is essentially the same in bleached and unb]eached rock. (Chemical analyses
of Entrada sandstone from the Rifle mine, Garfield County, Colorado, show
that a similar change took place where red sandstone was bleached along
fractures). Since the Fe(III) hydrolyzes readily and reprecipitates as
the hydrous oxide, the removal of the hematite probably involved reduction
of the iron to Fe(II) which does not readily hydrolyze and which was
removed in solution.
The large amount of Fe(III) remaining in sample 5* a bleached sample
(Table U), is explained by the presence in the rock of a large amount of
biotite which imparts a green color to the rock and contains both Fe(Il)
and Fe(III). The biotite has remained unaffected by the solutions which
removed the hematite. Sample 6 contained about the same percentage of biotite ,
but the green color was masked by the hematite.
The distribution of bleached and unbleached country rock is irregular.
In places layers of white are intermixed with layers of red; in other places
rounded or lens-shaped patches of white may be surrounded by red sandstone.
The white patches and layers do not appear to be related to any fracture
pattern. Here hematite may never have been deposited or hematite may have
been deposited and later removed. Evidence favoring either hypothesis is
lacking.
Specimens 3 and U are from an area in the Honeybee No. 2 mine in which
the bleaching is definitely fracture-controlled (fig. 16). Solutions travell¬
ing along irregular fractures in and near the fault caused bleaching in zones
beginning at the fracture surfaces and extending up to several inches on
each side.
The hematite in the biotite schist is distributed quite irregularly,
but is mostly in lenses and streaks with the longer dimensions parallel to
the planes of schistnsity which in turn parallel the fault. Most fractures
are healed and are not visible either megascopically or microscopically.
In the vicinity of the fault, the rock is definitely less red than at
a distance from the fault. Evidently the solutions causing the bleaching
in the fault-zone travelled through the open spaces Droduced by faulting.
The association of the bleaching solutions to ore-bearing solutions is
unknown; both followed fractures in the fault zone ani were, therefore, of
post-fault age. Ore-bearing solutions may have produced the bleaching, or
the bleaching may have been produced by other solutions passing through the
- 40 -
same zone before and/or after mineralization. It is doubtful that ore-
bearing solutions were responsible for the differences in color in the country
rock since these differences were found in the Cutler formation miles away
from the faulted area.
The gray-green coloration in the lower part of the Chinle, which transects
both bedding planes and lithologic variations within beds, is reported to
be of maximum intensity on the northeast flank of the Cane Creek anticline
in the vicinity of the Cane Creek fault (McRae, 1958). This alteration was
not stuaied by the author since the major ore bodies on the east side of Cane
Springs Canyon are not in the Chinle.
SUMMARY
1. The uranium was introduced into the Cane Springs Canyon area after
formation of the structural features of the area. Baker (1933) says that
t he present structural features were essentially formed by the end of
Cretaceous time. The age determination by J. L. Kulp dates the mineral¬
ization of the Honeybee mine as late Paleocene or early Eocene. The mineral¬
ization in the other mines is probably of the same age.
2. The deposits are vein-type and occur along faults and fractures.
3. The mineralizing solutions travelled through openings provided by
faulting and fracturing. The solutions may well have cane from below since
all exposed formations from the Moss Back down contain uranium, but non*
has been found in formations above the Moss Back.
4. Uranium was precipitated by local reducing conditions produced by
organic material an<4 possibly, by hydrogen sulfide.
5. The organic matt r is now pyrobitumen, probably of plant origin,
some of which migrated p rt distances in a fluid or plastic state.
6 . Bleaching, due to removal of hematite, is more cannon near the
faults. The bleaching in and near the fault zones is spatially related to
the faults, as is the mineralization, but the two are not necessarily
otherwise related to each other.
- 41 -
r
Fig. 5. Calcite-cemented sandstone in which calcite (ca) has
partly or wholly replaced some of the detrital grains (d). Outline of
replaced grains preserved by thin film of hematite. HoneyV ’e mine.
Thin section. Crossed Nicola. X107.
- 42 -
!tween calcite crystals (medium-gray) filled with
Honeybee mine. Polished section. X225.
Pig. 9. Mass of ■ontroseite (mr) which has replaced biotite (bi)
along cleavage planes, veined by chalcopyrite (cp). Honeybee mine. Polished
section. X135.
Fig. 10. Uraninite (light-gray blebs) and chalcopyrite (nearly white)
in pyrobitumen matrix. Honeybee mine. Polished section. X225«
fig* 11• Chalcopyrite (cp) veining submicroscopically intergrown
uraninite—pyrobitumen (pb j. U r- aninite (light—gray) also replaces quartz
grain (qt). Honeybee mine. Polished section. X225.
- 45 -
Fig. 12. Chalcopyrite (cp) and uraninite (u) pseudomorphs after
barite. Chalcopyrite contains disseminated galena (lighter gray).
Honeybee mine. Polished section. X225.
I
Fi*. 13. Uraninite veinlet (u) extending from pyrobitumen (pb)
into biotite achist (bi a). Black spota are pita in aection. Honey¬
bee mine. Poliahed aection. X135-
Fig. 15. Uraninite (medium gray) finely disseminated in pyrobitumen
(slightly darker shade of gray) and ankerite (dark gray). Chalcopyrite
(white) in barite (ba). From fault zone in Honeybee mine. Polished
section X225.
Fig. 16. Honeybee No. 2 mine located along minor fault which strikes
east and dips north.
-47-
Fig. 17. Honeybee No. 2 mine. Ferruginous red sandstone (dark)
has been bleached along fractures to low-iron, white sandstone.
Fig. 18. Fossil wood replaced by uraninite (light-gray), calcite
(dark-gray) and pyrite (nearly white). Note that the uraninite has filled
or nearly filled most of the cell. Pyrite and irregular patches of cal¬
cite have destroyed the cell texture. Moss Back adit. Polished section.
X135.
-48-
Fig. 19. Uraninite (light-gray) veined by organic matter (mediunw
gray). Widest dark veinlet is Beta-zippeite. Koss Back adit. Polished
section. X47-
„ V
r.- * —
- • ^ # V/ '
Fig. 20. Fossil wood in which uraninite (light-gray) ha 3 partly or
wholly replaced the cells. The cell walls are calcite (dark-gray) and
pyrite (white). The cell structure has been distorted or destroyed in
some places. Moss Back adit. Polished section. X135*
Fig. 22. Pyrite (white) which has precipitated alternately with
calcite (medium-gray) on successive faces of growing calcite crystals.
Moss Back adit. Polished section. X107*
21. Longitudinal section of fossil wood with cell structure
preserved by pyrite (white). Veinlet of pyrite cuts across cell texture.
Pyrite is partly altered to hematite (light-gray). Moss Back adit.
Polished section. X47.
Fig. 25. Marcasite (light-gray) precipitated alternately with
calcite (medium-gray matrix). Moss Back adit. Polished section. X107.
Fig. 26.
Calcarenite. Adair mine. Thin section.
Crossed Nit.ols.
■ 7 . :
Fig. 27. Kontroseite (mr) and calcite (ca) cementing sandstone.
Uraninite (ur) has partly replaced argillaceous limestone grain which
is veined by calcite and montroseite. Adair mine. Polished section.
Fig. 28. Fossil wood in which uraninite (light-gray) and chalcopyrite
(white) have replaced cell walls, and calcite (dark-gray) and pyrite
(vhite) have repl-oed cell -enters. Chalcopyrite and pyrite are same
shade in figure. Black sp ts are pits in section. Adair mine. Polished
section X135*
rig. 30. Fossil wood replaced by uraninite (light-gray), chalcopy-
rite and pyrite (both white), and calcite (medium-gray). Chalcopyrite
replaces cell walls in lower right. Pyrite masses enclose cell walls
replaced by uraninite. Black spots are pits in section. Adair mine.
Polished section. X135*
Fig. 31• Sandstone cemented by uraninite (light-gray) and calcite
(medi’un-gray). Uraninite and chaicopyrite (white) have partly replaced
many of the detrital grains. Adair mine. Polished section. Xi+7*
Fig. 33* Cell texture in fossil wood preserved in inner portion by
uraninite (u) and calcite (ca). Cell texture destroyed where pyrite (py)
crystals occur in uraninite. Adair mine. Polished section. X135.
Fig. 34 . Fossil wood replaced by uraninite (light-gray) and calcite
(medium-gray). Galena (white) in calcite. Adair mine. Polished section
Fig. 35. Sandstone cemented by uraninite (u) and calcite (ca). Urani-
nite and pyrite (py) have partly replaced many of the detrital grains, and
uraninite rims some grains. Climax School Section mine. Polished section.
X135.
Fig. 36 . Uraninite (light-gray), pyrite (white), and calcite (medium-
gray) cementing sandstone. Climax School Section mine. Polished section.
X135.
-5'
(white)
Section
Massive uraninite (u) cut by calcite (ca). Climax School
Polished section. X47*
Fig. 39. Pyrite (white), uraninite (light-gray), ani calcite (dark-
gray) in fossil wood. Round blebs of uraninite penetrate the border of
the pyrite crystal. Climax School Section mine. Polished section. X 461
Fig. 40. Massive pyrite (while) veined by calcite (dark-gray) and
uraninite (light-gray). Uraninite along vanished faces of corroded pyrite
crystals and along faces of calcite crystals. Climax School Section
mine. Polished section. X225.
Uraninite (light-gray) along crystal planes of calcite
Climax School Section mine. Polished section. X135.
Fig. 41.
(medium-gray)
Fig. 42. Pyrite crystal (white) partly replaced by
gray) and calcite (medium-gray). Climax School Section i
section. X225«
Fig. 43* Pyrite crystals and masses (py) which have veined and partly
replaced uraninite (ur) in calcite (ca) matrix. Climax School Section mine
Polished section. X225*
Fig. 44* F'jnnants of wood cell texture. 'Jraninite (light-gray), cal¬
cite (dark-gray) and pyrite (white). Black spots are pits in section.
Climax School Section mine. Polished section. X135.
Veinlet of Beta-zippeite (bz) in sandstone. Climax School
Thin section. X225.
Fig. 47
Section mine
Boltwoodite needles in gypsum (gp) veinlet cutting sand-
by Beta-zippeite (bz). Climax School Section mine. Thin
Jr
A
.
REFERENCES
Abraham, H. (1945), Asphalts and allied substances: D. Van Nostrand and Co.,
Inc. Princeton, N. J.
Baker, A. A. (1933), Geology and oil possibilities of the Moab district. Grand
and San Juan Counties, Utah, U. S. Geol. Survey Bull. 84x.
Barth, Tom, F. W. (1952), Theoretical petrology: John Wiley and Sons, Inc., N.Y.
Easons, W. H. (1949), Principles of economic geology: McGraw Hill Book Co.,
N. Y.
Frondel, Clifford (1956), Mineral Composition of Guamite: Am. Mineral. 41,
539-568.
Frondel, Clifford, and Ito, J. (1956), Boltwoodite, a new uranium silicate
Science 124, 931.
Frondel, Clifford, Riska, Daphne, and Frondel, Judith W. (1956), Powder
data for uranium and thorium minerals: U. S. Geol. Survey Bull. 1036-G.
Harker, Alfred (1939), Metamorphism: E. P. Dutton and Co., Inc., N. Y.
Lindgren, Waldemar (1933), Mineral deposits: McGraw-Hill Book Co., N. Y.
McRae, Otis (revised by Isachsen,
veins in Cane Springs Canyon,
Y. W.) (1958), Investigation of uranium
San Juan County, Utah: U.S.A.E.C., RME-106
Palache, Charles; Berman, Harry; Frondel, Clifford (1951), The system of
mineralogy; 7th Ed., Vol. II: John Wiley and Sons, Inc., N. Y.
Ramberg, Hans (1952), The origin of metamorphic and metasomatic rocks: The
University of Chicago Press, Chicago.
Turner, Francis (1948), Mineralogical and structural evolution of the
metamorphic rocks: Geol. Soc. Am. Memoir 30.
Turner, Francis, and Verhoogen, Jean (1951), Igneous and metamorphic
petrology: McGraw-Hill Book Co., N. Y.
Van Krevelen, D. W„, and Schuyer, J. (1957), Coal science, Elsevier Publ.
Co., N. Y.
Williams, Howell; Turner, Fr ncis; and Gilbert, Charles (1954), Petrography:
W. H. Freeman and Co., San Francisco.
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